alnum: broken?

[Stephen Leake]

I'm attempting to generalize the regular expressions in ada-mode to
handle utf-8; some are currently limited to ASCII.

However, :alnum: appears to be broken:

(let ((text "01abCDE")
      res1 res2)
  (string-match "[:alnum:]+" text)
  (setq res1 (match-string 0 text))
  (string-match "[0-9a-zA-Z]+" text)
  (setq res2 (match-string 0 text))
  (list res1 res2))

gives:

("a" "01abCDE")

I'm running emacs master on Windows 8 x64.

I'm guessing this might be affected by the font: (frame-parameter nil 'font)
reports:
"-raster-Courier-normal-normal-normal-mono-13-*-*-*-c-*-iso8859-1"


On the other hand, running in a Debian testing VM on the same machine
gives the same results, and the font is
"-PfEd-DejaVu Sans Mono-normal-normal-normal-*-11-*-*-*-m-0-iso10646-1"

What am I missing?

-- 
-- Stephe